Subendocardial Ischemia Because of Coronary Artery Spasm Causes Transient Severe Mitral Regurgitation

Paroxysmal Severe Mitral Regurgitation

“…Coronary vasospasm or microvascular dysfunction has been the proposed mechanism in 6 prior cases due to reproduction with methergine, resolution with nitrates, ST-segment depression on electrocardiogram, and/or post-mortem autopsy findings of global subendocardial ischemia. 3,7,8,10 It is notable that most patients in our series and previous reports are postmenopausal women with cardiac risk factors, a population that is particularly prone to coronary vasomotor dysfunction. 13 There were not enough data to speculate the mechanism in 3 prior cases, although all had severe apical tenting that mirrored the pathophysiology of type 1 or type 3.…”

“…Five patients were postmenopausal women with significant cardiac risk factors, which is similar to the demographics of previous case reports. [3][4][5][6][7][8][9]11,12 Our case series highlights 3 distinct mechanisms leading to the development of paroxysmal severe MR. Type 1 was caused by LV dyssynchrony from an LBBB, which led to apical tenting and incomplete coaptation of the MV leaflets.…”

“…Although there have been only 17 reported cases to date, it is unclear how many cases have been missed. [3][4][5][6][7][8][9][10][11] The underlying pathophysiology and optimal treatment for the condition are currently unknown.…”

Not Your “Run-of-the-Mill” Mitral Regurgitation

“…Along with transient epicardial coronary vasospasm and microvascular dysfunction mentioned earlier, other acute changes in the immediate postbypass period, such as intracoronary air combined with transient myocardial ischemia, must also be considered to explain the sudden apical tenting and lack of MV coaptation. [10][11][12][13] This example would again serve as a reminder that the pathophysiological mechanism of eclipsed MR is still not fully understood.…”

“…While the changing severity of MR in eclipsed MR is often seen during a single imaging study, as was shown in the case presented by Arias-Godinez and colleagues, repeat assessment by echocardiography may be warranted to appreciate the transient nature of the MR. 9 Along with the transient quality (typically lasting less than 30 minutes), other hallmarks of eclipsed MR would demonstrate severe, functional MR that is reversible. [11][12][13] When other "run-of-the-mill" causes of secondary MR do not apply, eclipsed MR should be considered if these criteria have been met. Given the limited reporting of eclipsed MR, cases such as the E-challenge presented in this issue are welcome to further allow clinicians to appreciate, and potentially diagnose, this rare cause of MR. 9…”